It is known that transducers include a coil with a first air gap or tunnel, magnetic members, such as spaced apart permanent magnets, having a second air gap or tunnel, and a reed armature. The first and second air gaps are generally aligned, with the armature reed extending through the first and second aid gaps.
The arrangement is such that when the moving part of the reed shifts in one direction or another away from a centralized position between the two poles, the magnetic flux is caused to flow in one direction or the other along the reed and hence through the coil. The reed is attached to a diaphragm and in this way the vibrations of the diaphragm caused by received sound are converted into corresponding currents in the coil or vice versa. If the transducer experiences a shock e.g., from being dropped, the reed can be easily damaged due to over deflection or unwanted deflection in the horizontal and/or vertical directions. In addition, the tip portion of the reed may strike the magnet with considerable force on the upper or lower side walls of the tunnel formed within the coil. Reference may be made to U.S. Pat. No. 5,647,013 for one such arrangement.
To reduce and prevent unwanted deflection of the armature's reed, the tunnel of the transducer can be tapered (inwardly or outwardly) from the fixed or stationary end of the armature toward the deflection end of the reed. In addition, a contact point can extend into the tunnel to reduce or prevent unwanted horizontal deflection of the armature reed. These previous techniques still require the reed to contact the surface of the tunnel and this contact can cause damage to the reed.
This invention is designed to prevent these and other problems.